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P38 MAP kinase signaling is required for the conversion of CD4+CD25- T cells into iTreg.

Huber S, Schrader J, Fritz G, Presser K, Schmitt S, Waisman A, Lüth S, Blessing M, Herkel J, Schramm C - PLoS ONE (2008)

Bottom Line: Inhibition of p38 MAP kinase activity prevented the TGF-beta-dependent conversion of CD4+CD25- T cells into Foxp3+ iTreg in vitro.Of note, the suppressive capacity of nTreg was not affected by inhibiting p38 MAP kinase.Our findings indicate that signaling via p38 MAP kinase seems to be important for the peripheral generation of iTreg; p38 MAP kinase could thus be a therapeutic target to enhance immunity to chronic viral infection or cancer.

View Article: PubMed Central - PubMed

Affiliation: I. Medizinische Klinik, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany.

ABSTRACT
CD4+CD25+ regulatory T cells (Treg) are important mediators of immune tolerance. A subset of Treg can be generated in the periphery by TGF-beta dependent conversion of conventional CD4+CD25- T cells into induced Treg (iTreg). In chronic viral infection or malignancy, such induced iTreg, which limit the depletion of aberrant or infected cells, may be of pathogenic relevance. To identify potential targets for therapeutic intervention, we investigated the TGF-beta signaling in Treg. In contrast to conventional CD4+ T cells, Treg exhibited marked activation of the p38 MAP kinase pathway. Inhibition of p38 MAP kinase activity prevented the TGF-beta-dependent conversion of CD4+CD25- T cells into Foxp3+ iTreg in vitro. Of note, the suppressive capacity of nTreg was not affected by inhibiting p38 MAP kinase. Our findings indicate that signaling via p38 MAP kinase seems to be important for the peripheral generation of iTreg; p38 MAP kinase could thus be a therapeutic target to enhance immunity to chronic viral infection or cancer.

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Related in: MedlinePlus

Signaling via p38 MAP kinase is required for the in vitro conversion of CD4+CD25− T cells into TGF-beta1-induced Foxp3+ Treg (Ti Treg).CD4+CD25− T cells were activated with plate bound anti-CD3 mAb (2 µg/ml) and soluble anti-CD28 mAb (2 µg/ml) for 4 days in the presence or absence of TGF-beta1 (2 ng/ml). Kinase inhibitors were added every 12 h (SB203580 (10 µM), SP600125 (10 µM), PD89059 (50 µM)). A: Schematic experimental procedure. Ti Treg: TGF-beta-induced Treg. B: Foxp3-expression and in vitro suppressor assay using CD4+CD25− CFSE-labelled responder T cells isolated from spleen and suppressor T cells generated by in vitro conversion as described above. Cells were washed three times before adding to the culture. Responder and suppressor cells were added at the indicated ratios [×105]. Data are representative of three independent experiments using SP600125, PD89059, SB202190 and five independent experiments using SB203580.
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pone-0003302-g003: Signaling via p38 MAP kinase is required for the in vitro conversion of CD4+CD25− T cells into TGF-beta1-induced Foxp3+ Treg (Ti Treg).CD4+CD25− T cells were activated with plate bound anti-CD3 mAb (2 µg/ml) and soluble anti-CD28 mAb (2 µg/ml) for 4 days in the presence or absence of TGF-beta1 (2 ng/ml). Kinase inhibitors were added every 12 h (SB203580 (10 µM), SP600125 (10 µM), PD89059 (50 µM)). A: Schematic experimental procedure. Ti Treg: TGF-beta-induced Treg. B: Foxp3-expression and in vitro suppressor assay using CD4+CD25− CFSE-labelled responder T cells isolated from spleen and suppressor T cells generated by in vitro conversion as described above. Cells were washed three times before adding to the culture. Responder and suppressor cells were added at the indicated ratios [×105]. Data are representative of three independent experiments using SP600125, PD89059, SB202190 and five independent experiments using SB203580.

Mentions: We therefore next analyzed the role of p38 MAP kinase signaling for the conversion of CD4+CD25− T cells into Foxp3-expressing iTreg in vitro (Figure 3A). CD4+CD25− T cells were cultured for four days in the presence or absence of TGF-beta1. The role of p38 signaling was investigated by adding the specific p38 inhibitors SB203580 or SB202190 to the cultures twice daily. Alternatively, ERK inhibitor PD98059 or JNK inhibitor SP600125 was added to the culture. The rates of conversion into iTreg were determined by flow cytometric analysis of Foxp3-expression and assessment of the functional suppressive activity of the induced cells in vitro (Figure 3B).


P38 MAP kinase signaling is required for the conversion of CD4+CD25- T cells into iTreg.

Huber S, Schrader J, Fritz G, Presser K, Schmitt S, Waisman A, Lüth S, Blessing M, Herkel J, Schramm C - PLoS ONE (2008)

Signaling via p38 MAP kinase is required for the in vitro conversion of CD4+CD25− T cells into TGF-beta1-induced Foxp3+ Treg (Ti Treg).CD4+CD25− T cells were activated with plate bound anti-CD3 mAb (2 µg/ml) and soluble anti-CD28 mAb (2 µg/ml) for 4 days in the presence or absence of TGF-beta1 (2 ng/ml). Kinase inhibitors were added every 12 h (SB203580 (10 µM), SP600125 (10 µM), PD89059 (50 µM)). A: Schematic experimental procedure. Ti Treg: TGF-beta-induced Treg. B: Foxp3-expression and in vitro suppressor assay using CD4+CD25− CFSE-labelled responder T cells isolated from spleen and suppressor T cells generated by in vitro conversion as described above. Cells were washed three times before adding to the culture. Responder and suppressor cells were added at the indicated ratios [×105]. Data are representative of three independent experiments using SP600125, PD89059, SB202190 and five independent experiments using SB203580.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2553190&req=5

pone-0003302-g003: Signaling via p38 MAP kinase is required for the in vitro conversion of CD4+CD25− T cells into TGF-beta1-induced Foxp3+ Treg (Ti Treg).CD4+CD25− T cells were activated with plate bound anti-CD3 mAb (2 µg/ml) and soluble anti-CD28 mAb (2 µg/ml) for 4 days in the presence or absence of TGF-beta1 (2 ng/ml). Kinase inhibitors were added every 12 h (SB203580 (10 µM), SP600125 (10 µM), PD89059 (50 µM)). A: Schematic experimental procedure. Ti Treg: TGF-beta-induced Treg. B: Foxp3-expression and in vitro suppressor assay using CD4+CD25− CFSE-labelled responder T cells isolated from spleen and suppressor T cells generated by in vitro conversion as described above. Cells were washed three times before adding to the culture. Responder and suppressor cells were added at the indicated ratios [×105]. Data are representative of three independent experiments using SP600125, PD89059, SB202190 and five independent experiments using SB203580.
Mentions: We therefore next analyzed the role of p38 MAP kinase signaling for the conversion of CD4+CD25− T cells into Foxp3-expressing iTreg in vitro (Figure 3A). CD4+CD25− T cells were cultured for four days in the presence or absence of TGF-beta1. The role of p38 signaling was investigated by adding the specific p38 inhibitors SB203580 or SB202190 to the cultures twice daily. Alternatively, ERK inhibitor PD98059 or JNK inhibitor SP600125 was added to the culture. The rates of conversion into iTreg were determined by flow cytometric analysis of Foxp3-expression and assessment of the functional suppressive activity of the induced cells in vitro (Figure 3B).

Bottom Line: Inhibition of p38 MAP kinase activity prevented the TGF-beta-dependent conversion of CD4+CD25- T cells into Foxp3+ iTreg in vitro.Of note, the suppressive capacity of nTreg was not affected by inhibiting p38 MAP kinase.Our findings indicate that signaling via p38 MAP kinase seems to be important for the peripheral generation of iTreg; p38 MAP kinase could thus be a therapeutic target to enhance immunity to chronic viral infection or cancer.

View Article: PubMed Central - PubMed

Affiliation: I. Medizinische Klinik, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany.

ABSTRACT
CD4+CD25+ regulatory T cells (Treg) are important mediators of immune tolerance. A subset of Treg can be generated in the periphery by TGF-beta dependent conversion of conventional CD4+CD25- T cells into induced Treg (iTreg). In chronic viral infection or malignancy, such induced iTreg, which limit the depletion of aberrant or infected cells, may be of pathogenic relevance. To identify potential targets for therapeutic intervention, we investigated the TGF-beta signaling in Treg. In contrast to conventional CD4+ T cells, Treg exhibited marked activation of the p38 MAP kinase pathway. Inhibition of p38 MAP kinase activity prevented the TGF-beta-dependent conversion of CD4+CD25- T cells into Foxp3+ iTreg in vitro. Of note, the suppressive capacity of nTreg was not affected by inhibiting p38 MAP kinase. Our findings indicate that signaling via p38 MAP kinase seems to be important for the peripheral generation of iTreg; p38 MAP kinase could thus be a therapeutic target to enhance immunity to chronic viral infection or cancer.

Show MeSH
Related in: MedlinePlus